This invention relates to a discharge chute for a material grinding apparatus and more particularly to a discharge chute for a coffee grinder.
The popularity of and the demand for freshly ground coffee has grown substantially and continues to grow. Many retail establishments, such as supermarkets, restaurants and specialty shops, have coffee grinders for roasted coffee beans providing freshly ground coffee on demand. Freshly ground coffee provides recognizably preferable characteristics over preground coffee.
Many types of coffee beans have a thin membrane which dries during the roasting process. Upon grinding of the coffee beans, the thin membrane is separated from the rest of the coffee bean creating a light bean debris which separates therefrom during grinding. The dried, ground membrane is commonly called chaff. Chaff does not detract from the flavor of coffee, however, due to its light weight, it is prone to being separated from the ground coffee discharged from the grinder to a container waiting therebelow. Free floating chaff can create problems within the grinder and therefore it is desirable to retain the chaff within the bulk of the ground coffee. Further, it is desirable to retain chaff in the coffee in order to help reduce caking problems which typically occurs in ground coffee as it is discharged from the grinder.
Prior art devices have attempted to combat chaff problems by keeping the chaff mixed with the coffee as it is discharged from the coffee grinder. One example of a prior art device which attempts to conquer chaff problems is shown in U.S. Pat. No. 4,813,622 to Nidiffer et al. As shown in Nidiffer et al., a flat steel spring covers a discharge opening from the grinder to a discharge chute. The flat steel spring packs the coffee to some degree as it exits the discharge opening prior to entering the discharge chute. The spring creates a buffer preventing air currents from separating the chaff and creates a more continuous stream of ground coffee discharged therefrom.
While the device as shown in Nidiffer et al. is generally satisfactory, a remaining problem exists in that an amount of ground coffee is retained above the flat steel spring after grinding. This amount of coffee mixes with the next grind of beans creating an undesirable mixture of beans should the two sequential grinds be of dissimilar bean type. An example of the undesirability of this problem is especially prominent when a dark roasted coffee bean is finely ground and is followed by a grind of a coarse grind of a lightly roasted bean. In such a scenario, the dark roasted bean, unintentionally mixed in with the light bean, is quite prominently pronounced and when the light bean is brewed, may create an undesirable taste.
Further, prior art devices attempting to resolve the chaff separation problem tended to be ineffective for extra fine grinds such as expresso or Turkish grinds. With an expresso or Turkish grind, the coffee tends to pack together and thus force the chaff mixing spring into its open position. Due to the arrangement of a clean-out plunger as mentioned below, the blockage typically could not be removed requiring disassembly of the mechanism upon this occurrence.
Additionally, the prior art as shown in the device in Nidiffer et al. provides a baffling arrangement which deposits the coffee into a channel-shaped section of the discharge chute whereupon the discharged coffee may be exposed to air currents caught within the chute. The air currents caught within the channel-shaped portion of the discharge chute tend to separate the chaff thereby defeating the initial purpose of the flat steel spring as mentioned above.
In an attempt to resolve the problem of retaining coffee above the flat steel spring, a chaff plunger was added a baffle to which a lever was attached. Movement of the lever moved the plunger through the discharge opening in the grinder. Such movement of the plunger dislodged caked ground coffee packed within the chamber and tended to remove some of the coffee accumulated above the flat steel spring. However, due to the configuration of the plunger and flat steel spring, an amount of coffee still remained above the flat steel spring and would inevitably be mixed with the next grind of beans.